lib/PublicInbox/Inbox.pm | 1 +

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index 5503980fc0ca3d297d6062709b3dfacb44aae800..008a6cf7061335c33ae7fcf54ed7c37204f29b3d 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -60,6 +60,7 @@ sub _set_limiter ($$$) {
 	my ($self, $git, $pfx) = @_;
 	my $lkey = "-${pfx}_limiter";
 	$git->{$lkey} = $self->{$lkey} ||= eval {
+		# full key is: publicinbox.$NAME.httpbackendmax
 		my $mkey = $pfx.'max';
 		my $val = $self->{$mkey} or return;
 		my $lim;